Headers and a tuner
 

I'm about to purchase a set of Dynatech SuperMAXX headers and catted mid pipe for my 2008 5.4L. I'll also be purchasing a pair of Borla Pro-XS mufflers. Basically redoing my current exhaust with Maggie high flows and x pipe with 5x11 ovals. My question is do I need a custom tune at this time? Yes I understand it will unlock a lot of potential, and I will be getting a tuner sooner than later. But the question is is it necessary with the exhaust like it would be with an intake to prevent a further lean A/F ratio? My passenger manifold is leaking and a weld on the driver's side high flow has developed a pin hole, so things need to happen soon. But obviously setting back the $1500 on headers and mid pipe, $200 on mufflers, plus tips and piping, I'll be pudhing a bit over $2k, and the $4-600 depending on the tuner right now just isn't available. My instinct tells me no, it's not NEEDED, but is highly recommended for performance. Is this correct? Thanks

Correct.

My guess is you'll gain nothing without a CUSTOM tune.

9 out of 10 trucks will be fine with long tube headers, it's the one out of 10 that will throw a code. A tuner with custom tunes is the correct fix, but you can try MIL eliminators or spark plug extensions as a temp fix until you have the funds to get a tuner. But you may be in the majority and not need anything. You won't know until you get the headers on.

What I will gain, 329PD, is no more leaking passenger manifold and no more pinhole in the current high flow. Like I said, the concern right now is fixing the exhaust and tuning later.

Just picked up the exhaust manifold gaskets and new bolts from Ford, hopefully this will all take place asap

You will get that for sure. I had a warped exhaust manifold. I think it cost me 300 to fix at my favorite local shop.

I was under the impression you wanted to take advantage of headers, exhaust, intake, etc. The way to do that is with a custom tune. It woke up mine big time and that's on a bone stock rig. "Driveability" was improved, for lack of a better term. Other great side benefits are being able to adjust shift firmness, tire size, and axle ratio.

You are also correct; drive it with your mods, then later, should you decide, tune it.

Is a tuner required, I would think not.

You're absolutely right, I want the most I can get from the mods, but again, after the headers and mid pipe with x pipe, dual Borlas and fab work, I'm already over $2K. The $4-$600 for tuner and custom tunes just isn't in the budget this month. The issue was driveability in the meantime without codes. I could repair with a stock manifold but why not start the upgrades now?

Yup, sounds like an awesome start. I can't answer the trouble code question. I'd love to hear what your results are after the install and again after a custom tune. I bet you go from grin to bigger grin once you unlock your mod's potential. :woot:

With headers and high flow cats, you may or may not get a CEL with a P0420 and/or P0430. This will not affect the way it runs, and can possibly be eliminated with the Gotts O2 Mod. You have a better chance of no CEL if you get high flows that have bungs for the O2's. You only NEED tunes if you get an aftermarket intake, without them it will run too lean.

The OEM software system is designed to adjust the fuel mixture up to 10% (25% on the 2000+ mod engines).......that’s more than enough to handle fuel mixture adjustments up to 7,000 foot elevation change! (for high elevations 8,000+ there are oem software programs for those specific applications).

In a word, no, there is absolutely no way even running straight pipes with headers would be outside of the ability of the ECM to maintain correct A/F mixture.

Correct, but with an aftermarket INTAKE on a 5.4 3 valve, it will run too lean without custom tunes due to MAF transfer issues.

That would be all correct to go for just keep the thing

I did the exact thing you are doing on 2007 5.4. When my manifold rusted out I replaced with bolt on headers and high flow cats and Borla exausts I got from Troyer. When I sent my tuner to be updated I went without a tune for about a month and was fine no codes. The cat converters on our trucks are expensive by doing this I saved about $800 by going ahead and replacing the oem cats with high flow Magna Flow cats that came with bolt on headers. You will want a tune to get the most out of this set-up.